Almost made a minimug tonight...

Well, I've finally gotten the major bugs worke dout of Lamarck and tried a couple of attempts at a minimug. The overall shape was pretty good, but I'm running into an interesting issue, and I was hoping that someone with knowledge of the software might be able to assist.

In printing the circular sections for the minimug, it seems to pause for a fraction of a second between angle changes. As an example, if it is approximating a circle by printing at 0 degrees for a length, then 15, then 30, then 45, then 60, and so forth, it will pause for about 1/4 of a second between the print at 0 degrees and the one at 15, and between 15 and 30, and so on. This slows down the overall speed of the extrusion enough that it is dumping too much material on each segment. Is there anything like a preference setting that would change this, or is it a bug in the software itself?

i believe that is due to a problem that adrian is working on right now. right now, the host software has to send out each new coordinate after its done on it. we're changing that so it sends out a few at a time, and the axis stores that in a buffer, so it can seamlessly go to the next line.

It shouldn't be taking a quarter of a second for the PIC to receive and process a serial move instruction over the ring, even at 4 Mhz. After all the serial link is running at 19.2 Kbit/sec, IIRC. I wonder if there is some other delay in the firmware that isn't obvious causing the delay.

It might be worth turning on CommsDebug and capturing the output for later analysis, so we can see what exactly the host software is asking the PICs to do when, and when the ACKs come back... so then we'll know if any of the delay is in the host?

Hmmm, it would be helpful if that debug output included timing info, wouldn't it... I can add that... [15 mins later] OK, done and tested :-)

This forum still won't let me attach files... grrr.

OK: [www.box.net] will let you grab the package I just made, and [www.box.net] will get you the modified SNAPCommunicator.java it uses.

Jonathan